1. Field of the Disclosure
The present disclosure relates to encoding media data depending on a bandwidth between a data transmission source communication apparatus and a transmission destination communication apparatus, as well as a storage medium.
2. Description of the Related Art
The volume of data that a communication apparatus can transmit over a network per unit of time is referred to as an available bandwidth (in bps). The number of bits that a communication apparatus conveys per unit of time over a network is referred to as a transmission bit rate (in bps). A transmission bit rate higher than the available bandwidth causes problems such as data congestion, packet loss, etc. A transmission bit rate lower than or equal to the available bandwidth might not be as susceptible to the problems of data congestion, packet loss, etc. However, if the transmission bit rate is significantly lower than the available bandwidth, the communication apparatus cannot make the best use of the available bandwidth (e.g., efficiency or effectiveness of bandwidth usage may be low). Accordingly, it is preferable that an encoding apparatus that encodes media data performs encoding in accordance with an available bandwidth that changes depending on the circumstances, such as an area, provider, and time zone, to adjust the transmission bit rate.
For example, a known moving-image distribution apparatus measures an available bandwidth by transmitting a fixed volume of moving-image data in burst manner and determining the amount of time required to complete the transmission. The transmission bit rate is adjusted on the basis of this measurement result.
If the setting of encoding conditions is changed to adjust a transmission bit rate to a target value, it takes a substantial amount of time before the transmission bit rate actually attains the target value. Even if the encoding apparatus continuously changes the setting of encoding conditions before the transmission bit rate attains the target value, the transmission bit rate cannot be suitably controlled. That is, suitable timing for changing the setting of encoding conditions might not be achieved. The time required to measure an available bandwidth sometimes changes under the influence of a network environment. Accordingly, it is also difficult for the encoding apparatus to acquire the measurement result of an available bandwidth in time to change the setting of encoding conditions. Thus, encoding apparatuses in the related art cannot change the setting of encoding conditions at suitable timing according to the measurement result of an available bandwidth.